Four-ball plastic hinge

ABSTRACT

An improved and more readily molded four-ball hinge for box sections is provided by arranging three elongated parallel grooves in one of the two sets of two balls, with one end of each groove being closed off by an abutment, and with one groove opening in a direction opposite to the opening direction of the other two grooves. All of the grooves are provided inwardly of the outermost portions of the snapped-together hinge, and the balls of the hinge have substantially the same nominal diameter.

United States Patent t J acobsen 51 Jan. 25, 1972 [s 1 FOUR-BALL PLASTICHINGE [72] lnventor: Robert K. Jacobsen, 3l2l N. Nagle Ave.,

Chicago, Ill. 60634 [22] Filed: Feb. 12, 1970 [21] Appl. No.2 10,931

[52] US. Cl ..l6/l7l [51] Int. Cl ..E05d 1/06 [58] Field otSearch..l6/l71, l28;220/3l SR [561 References Cited UNITED STATES PATENTS3,061,137 10/1962 Suoboda et a] ..230/31 SR 3,077,282 2/1963 Eggers16/128 13 3,179,28l 4/l965 Suoboda et al ..230/3l SR Primary ExaminerBobby R. Gay Assistant ExaminerDoris L. Troutman Attorney-Norman Lettvin[57] ABSTRACT An improved and more readily molded four-ball hinge forbox sections is provided by arranging three elongated parallel groovesin one of the two sets of two balls, with one end of each groove beingclosed off by an abutment, and with one groove opening in a directionopposite to the opening direction of the other two grooves. All of thegrooves are provided inwardly of the outermost portions of thesnappedtogether hinge, and the balls of the hinge have substantially thesame nominal diameter.

1 Claims, 4 Drawing Figures PAImIEums-mz 3,636,589

/2 6 I N VEN'TOR.

ROBERT K c/ACOBSEN ATTORNEY FOUR-BALL PLASTIC HINGE BACKGROUND OF THEINVENTION This invention relates to an improvement in a four-ball moldedhinge.

One of the objects of this invention is to provide improved molded hingemeans formed integrally with box sections, all

- molded of plastic material or the like, in which the hinge elementsmay be readily snapped into interlocking relationship, andparticulatized in having the arrangement of ball-receiving groovesaligned in parallel relationship so as to provide for improved facilityin molding and for simplicity in the construction of molds for formingthe same.

In US. Pat. Nos. 3,061,137 and 3,179,281 of which I am copatentee,ball-receiving grooves or recesses for the hinge are provided positionedat right angles to each other to insure interlocking of the hingeelements. The molding of such grooves or recesses at right angles toeach other poses problems and complexities both in molding of the partsand in constructing molds to effect proper molding of the parts, becausesuch prior constructions use moving pins in the molds, substantialflashing occurs, and substantial breakage has been noted.

This invention is an improvement over the constructions disclosed insaid patents in that all the grooves of the four-ball hinge of thisapplication extend in parallel relation to each other, with stability ofthe interlocked hinge parts being achieved by use of three elongatedabutment-ended, ballreceiving grooves arranged so that two of thegrooves on spaced balls of the hinge are mirror images and togetherdefine an open-ended socket for one ball, and the third groove openingin a diametrically opposite direction to one of the pair of said groovesand being located on the same ball member with said one of the pair ofgrooves.

Such a construction is simpler and less expensive to mold than the priorart hinges, as the moving mold-pins required for prior constructions areeliminated, and both flashing and breakage are materially reduced.

Further objects and advantages of this invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize this invention will be pointed out with particularity inthe claims annexed to and forming part of this specification.

A preferred embodiment of the invention is shown in the accompanyin gdrawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a boxutilizing two four-ball hinges made in accord with the instantinvention;

FIG. 2 is a rear elevational view of the box of FIG. 1;

FIG. 3 is an enlarged fragmentary cross-sectional view taken on line 3-3of FIG. 2; and

FIG. 4 is a fragmentary view partly in cross section taken on line 4-4of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,a plastic box is shown fonned of two identical molded sections 12 formedwith integral hinge portions. A description of only one section isnecessary, but the description of the interconnection of the portions ofthe ball hinge requires reference to both sections of the box.

Each section 12 of the box 10 is dish-shaped, providing a box-side 12aand a continuous side flange 12b that defines a portion of the boxsfront edge 12c, the boxs end edges 12d and the boxs rear edge 12. Theside flange 12b terminates in a peripheral edge 12f located in a flatplane and adapted to abut a similar edge on the opposite section 12.

The front edge 120 has formed integrally thereon means that comprise aclosure for the box. The means includes a pair of spaced elongatedretainers 14a adapted to resiliently receive therebetween an elongatedstub 14b that is positioned to have a portion thereof located outwardlyof edge 120 a distance greater than retainers 14a. To effect acooperative arrangement, retainers 14a are molded directly adjacentfront edge 12c and taper longitudinally from furthest outward extentadjacent the plane of edge 12f toward the box-edge 12c in a directionmoving away from edge 12f. The stud 14b, on the other hand, is locatedon an outwardly extending rib at a greater distance from box-edge 12cthan the projecting retainers 14a, and stud 14b extends longitudinallyfrom the plane of edge 12f in a direction opposite to the direction oftaper of the retainers 14a. The rib 14c, being cantilevered frombox-edge 120, provides sufficient resiliency to permit the stud 14 b topass over the ridge defined between the pair of retainers 14a to form areleasable lock for the box. By offsetting the center of the pair ofretainers 14a and center of stud 14b in equal opposite directions fromthe midlength of side 12c, identical sections 12 provide the box closureas seen in FIG. 1.

The boxs rear edge 12a is provided with two different hinge portions 16and 18 spaced equally from the closest adjacent end edge 12d.Considering the bottom section 12 seen in FIG. 2, the left-hand hingeportion is 16 and the right-hand portion is 18. Because of therotational arrangement of the upper section 12 relative to lower section12, the hinge portions thereon are reversed, so that each hinge portion16 cooperates with a hinge portion 18 to define each of the twofour-ball hinges, H, for the box.

The hinge portion 16 provides a pair of spaced, generally spherical,balls 16a and 16b each integrally molded at the extended end of atriangular brace-support 16c that projects outwardly of rear box-edge12a.

The hinge portion 18 also provides a pair of spaced balls 18a and 18beach integrally molded at the extended end of a triangular brace-support18c that projects outwardly of rear box-edge 12. But while the operativeportions of balls 16a and 16b provide only a spherical periphery, balls18a arid 18b are carefully formed to provide for and accommodate asnaptogether arrangement. Ball 180 is an outmost ball of the fourballhinge of FIG. 4, and it provides, on the inner side facing ball 18b, anelongated groove 20a with a seat, or curved abutment, 20b at one end.The other ball 18b is an inner ball being located between balls 16a and16b. Ball 18b is formed with elongated grooves 220 and 24a on oppositesides of ball 18b. The grooves 22a and 240 are parallel to each otherand to groove 20a. But grooves 22a and 24a, while each having one openend, open in opposite directions. Preferably groove 22a which facesgroove 20a opens in the same direction as groove 200. This constructionprovides that the curved abutments, or seats, 22b and 24b are arrangedso that they are diametrically opposite on the same ball 18b, but seat22b is on the same spherical curvature as 20b so as to form spacedsegments of a seat for the one interior ball 16b.

The foregoing structural arrangement permits the balls 16 and 18 to besubstantially of the same nominal diameter and has been found to providea very effective four-ball hinge that easily snaps together or apartwith a forcing pressure, yet provides a structurally stable four-ballhinge.

While there has been shown and described a particular embodiment of thisinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be made therein without departing from theinvention and, therefore, it is intended in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In integrally molded four-ball hinges for box sections wherein twospaced first balls carried by one box section interengage with twospaced second balls carried by asecond box section to provide asnapped-together hinge; the improvement comprising providing threeelongated grooves in the set of first balls lying in parallel relationto each other, each groove having one open end, for receivingtherethrough a portion of a ball of the set of second balls, and anabutment at the said one direction, each abutment at an end of a groovehaving a spherical curvature to serve as a socket portionfor a ball ofthe set of second balls, and the balls of both sets of balls havesubstantially the same nominal diameter.

1. In integrally molded four-ball hinges for box sections wherein twospaced first balls carried by one box section interengage with twospaced second balls carried by a second box section to provide asnapped-together hinge; the improvement comprising providing threeelongated grooves in the set of first balls lying in parallel relationto each other, each groove having one open end, for receivingtherethrough a portion of a ball of the set of second balls, and anabutment at the other end, the three grooves being arranged so that twoof the grooves open through their open end in one direction and arearranged to face toward each other on the set of first balls, the thirdgroove being on one of the set of first balls and opening through itsopen end in a direction diametrically opposite the said one direction,each abutment at an end of a groove having a spherical curvature toserve as a socket portion for a ball of the set of second balls, and theballs of both sets of balls have substantially the same nominaldiameter.